title: Early detection of central airway lung cancer in smokers with silicosis.
abstract: BACKGROUND
  Smokers with silicosis are at increased risk of lung cancer.
  
  
  OBJECTIVE
  To evaluate the feasibility of using autofluorescence bronchoscopy after sputum examination for early detection of large airway lung cancer and factors associated with the presence of cancerous and pre-cancerous lesions among smokers with silicosis.
  
  
  METHODS
  Subjects at the pneumoconiosis clinic were recruited if they fulfilled the following criteria: 1) age ≥40 years, 2) smoking history of ≥20 pack-years and 3) confirmed diagnosis of silicosis. Sputum specimens were collected for cytology/cytometry examination and autofluorescence bronchoscopy was performed in subjects with an abnormal sputum result.
  
  
  RESULTS
  A total of 48 subjects were recruited during the study period. The mean age and smoking history were respectively 63 ± 10 years and 51 ± 30 pack-years. Intraepithelial lung cancers and pre-neoplastic lesions (squamous metaplasia or above) were detected in respectively 2 (4.2%) and 14 (29.2%) subjects. The proportions of current smokers (75.0% vs. 40.6%, P = 0.03) and asbestos exposure (37.5% vs. 9.4%, P = 0.04) were significantly higher in subjects with the above lesions compared with those without.
  
  
  CONCLUSIONS
  Sputum examination followed by autofluorescence bronchoscopy may be a useful way of identifying cancerous/pre-cancerous lesions among silicotic smokers. Current smoking and asbestos exposure were associated with these lesions.
authors.affiliation: Department of Respiratory Medicine, Centro Hospitalar Conde de São Januário, Macao SAR, China.
authors.forename: A I L
authors.initials: AI
authors.lastname: Lo
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.forename: S Y
authors.initials: SY
authors.lastname: Lam
authors.forename: A H K
authors.initials: AH
authors.lastname: Cheung
authors.forename: R
authors.initials: R
authors.lastname: Au
authors.forename: C C
authors.initials: CC
authors.lastname: Leung
authors.forename: W K
authors.initials: WK
authors.lastname: Lam
authors.forename: M S M
authors.initials: MS
authors.lastname: Ip
authors.forename: M
authors.initials: M
authors.lastname: Chan-Yeung
authors.forename: B
authors.initials: B
authors.lastname: Lam
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001194:Asbestos / Q000633:toxicity; D001999:Bronchoscopy / Q000379:methods*; D055088:Early Detection of Cancer / Q000379:methods; D005240:Feasibility Studies; D005453:Fluorescence; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000175:diagnosis / Q000209:etiology / Q000473:pathology; D012307:Risk Factors; D012829:Silicosis / Q000150:complications*; D012907:Smoking / Q000009:adverse effects*; D013183:Sputum / Q000166:cytology
chemical_list: D001194:Asbestos